Machine for generating bevel-gears



M. MAAG AND R. FREY. MACHINE FOR GENERATING BEVEL GEARS.

APPLICATION FILED JAN. 30, 1920.

Patented Aug- 31, 1920.

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M. MAAG AND R. FREY. MACHINE FOR GENERATING BEVEL GEARS.

APPLICATION FILED JAN.30, I920.

Patented Aug. 31, 1920.

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MAX MAAG, or ZURICH, AND RICHARD FREY, or House, NEAR zUnIoH, SWITZERLAND.

MACHINE FOR GENERATING BEVEL-GEARS.

Specification of Letters Patent. Patented Aug. 31, 1920.

Application filed January 30, 1920. Serial No. 355,143.

T 0 all whom it may concern:

Be it known that we, MAX MAAG, a citizen of the Republic of'Switzerland, residing at Zurich, Hardstrasse 219, Switzerland, and RICHARD FREY, a citizen of the Republic of Switzerland, residing at Hijngg, near reference marked thereon, which form apart of this specification.

The present invention relates to a machine for producing the teeth of bevel-wheels which may be used for cutting, milling etc.

of bevel-wheel teeth on the generating method and'which is especiall adapted for grinding roughly cut teeth 0 the involute system. A machine according to the pres ent invention difiers from the heretofore known machines of this kind in the special manner ofderiving the oscillating and the rolling motion which insures a theoretically correct. curve being attained.

The accompanying drawings illustrate by way of example a mode of carrying this invention into effect, the machine shown working as a grinding machine.

Figure 1 is an elevation,

Fig. 2 is a 'plan,.

' Fig. 3 is a front view of this grinding machine, some parts thereof being shown in section,

Fig. 4 is a section on the line IVIV of Fig. 1'.

Upon the base-plate 1 of the grinding machine shown a movable table 3 with hearing arms 4 and 4 resting on a plain gliding face and being adapted to turn around a pivot 2 is provided. On said arms journals 5 and 5 are provided, on which a blank carried 6 is rotatably mounted. The position of said carrier may be altered by means of a toothed wheel mounted on the arm 4 and a toothed segment 8 cast in one with the carrier 6. Blank carrier 6 may then be fixed at a determined position by means of clamping-screw 9 moving in a slot of an arm 10 and extending into a projecting part 5 11 of the blank carrier.

with a segment 26, rotatably mounted on ducing the rolling movement of the blank. Upon a main driving shaft. 12 rotated by means of a belt-drive 13 and step pulley 14, a worm 15 is fixed, which imparts rotation to a crank disk 16 arranged as wormwheel. Turntable 3 is oscillated by means of this crank-disk and a connecting. rod 17. A segment 18 provided with cylindrical faces 19 of diiferent radius being concentrically arranged and fixed to the pivot 2, the latter being rigidly connected to the. base-plate 1.

A steel band 20 fixed at one end to one of these cylindrical faces 19 leads to a roll 21 fixed to a shaft 22. This shaft is journaled in the movable table 3 and transmits its rotation to a roll 23. A steel band 24 is fixed with one end to the latter roll and with the other to a roll 25. This roll 25 is,-together journal 5 and fixed to the latter in such a manner, that these two parts 25 and 26 may be adjusted against each other in the direction of their circumference, thus enabling the variation in the lengths of the bands at different positions of the rolling segment to be compensated. Another ,band 27 connects the rolling segment 26 to a roll 28 which is mounted on the blank carrier 6. As the rolling planes of the two bands 24 and 27 are perpendicular to each other, a block 29 and 30 respectively, provided with two slots inserted into each of the bands 24 and 27.

The radius of the rolling segment 26 may be altered by exchanging, z. 6. replacing it by another rolling segment of different radius. The extended breadth of the rollf28 provides for the various positions of the band 27 caused by the exchange of the roll ing segment 26. The roll 28 transmits the motion by means of a band 31 onto a lower horizontal slide of the hinged blank-carrier 6. A spring 33 actson the slide 32 tending to pull it toward the right. The spring 33 tightens all the above mentioned various steel bands and causes the return of slide 32 and of all the movable members connected to it. The motion of the lower slide 32 is transmitted to. an upper horizontal slide 34 by means of a compensating rule 35. This rule 35 is mounted on a pivot fixed on a sliding piece 36, which may be moved along a guide 37 of the blank-carrier 6 thus enabling, within certain limits, to alter the proportion of the lever-arms of the rule. Guide 37 and sliding piece 36 are provided with scales. The two horizontal slides 32,

j 34 are provided with shoes or rolls 38 which are pressed by means of springs 39 against. the rule 35. The axes of the pivot of the rule 35 and of the two rolls 38 are arranged in a straight line.

The horizontal arrangement of the slides 32, 34 insures all the weights to be balanced in any position of the hinged blank carrier. A case 40 carrying bands and a tightening device is mounted in a vertical guide-way in the slide 34. Bands'41 connect case 40 with a rolling segment 42. The latter is screwed on to a hollow spindle 43 in which the proper adjustable blank spindle is mounted by means of a clutch device.

drawings is arranged in a cylindrical part 45 on the rear end of the shaft 43.

The following device is provided for the purpose of producing the motion of the tool. A bevel-wheel 50 is mounted on the main driving shaft 12, which by means of a bevelwheel 51 drives an oblique shaft 53, transmit-.

ting the rotary motion by means of a bevel gear 52, 54 to a horizontal shaft 55. The.

latter imparts rotation to worm wheels '57 and 57 by means of worms 56 and 56", which worm wheels impart a reciprocating motion in the direction of the enveloping.

line or generatrix of the cone of the blank to two tool rams 60 and 60 by means of cranks 58 and 58 and connecting rods 59 and 59 Each ram is mounted in a prise matic guide 61 and 61 respectively which may be adjusted in the direction of the flank of a tooth by being turned around the vertical axis of the centering part 62 and 62 respectively.- A motor 63 and 63 respeceled around a longitudinal axis thus enablin any desired adjustment of the tool.

known feed device is, arranged for each grinding wheel within the parts and 70 respectively diagrammatically shown in Fig. 2. The above described drives are not substantially altered if only one tool-ram is pro vided. As shown in the figures the axis of the oscillating table 3'and the axis around which the blank carrier 6 swings pass through the vertex of the pitch cone.

The method of working of the described bevel-wheel grinding machine is as follows: In the described machine, like in most of the bevel-wheel machine tools, tool and blank A well knownautomatic'indexing or dividing device, which .is not shown in detail on the accompanylng a belt 64 and 64 respectively,

cone'travels along equal lengths of space.

around both axes of rotation. The planes of the grinding wheels represent the flank of a tooth of an imaginary stationary crown gear wheel on which the bevel gear being formed is rolled.

With the machine described by way of example, the movable table 3 is provided to carry out an oscillating movement by means of themain driving shaft 12, worm 15, worm wheel 16 and connecting rod 17. Steel band 20 moves on and off roll 21 because the shaft 22 with the rolls 21 and 23 fixed to it, takes part in that oscillating movement while, however, segment 18is stationary. This move ment is transmitted by means of roll 23 and band 24 on to roll 25 and to the rolling segment 26 connected "to the latter and from there by means of band 27 to roll 28. Themovement of roll 28 causes a rolling on or off hand 31, whereby the slide 32 is pulled to and fro, to one side by means ofthepull of the band 31 and to the other side'by the pull of spring 33. A movement of the table in the direction of the arrow A corresponds to a movement of the slide to the left. The

reciprocating movement of the lower slide 32 is transmitted to the upper slide 34, which carries the band-tightening device .40 by means of the rule 35; by means of the. bands 41 and rolling segment 42 an oscillating turning movement of the body of the bevel-wheel 71 is caused. The latter turns clockwise when table 3 swings in the direction of the arrow A. The two movements of the bevel-wheel 71, z'. e. the oscillating movement around its vertex and the rotating movement around its axis are each other.,

In order to get the proper ratio of the turning motions for various wheels and gearing, the fixed segment 18 is fitted with three cylindrical faces of different radii; furthermore segment 26 and segment 42 may be provided in several numbers having different radii, so that with comparatively fewexchangeable parts it is possible to arrange for the proper ratio of the two turnin motionsfor any bevel-wheel, the last and finest adjustment being attained by means of the rule 35. Thus change gear is dispensed with. Tools 68, 68 move ,to and fro along the flank of the tooth in the direction of the enveloping lines and in opposite sense, that is to say, if one of the rams "is in its front position (toward the bevel wheel) the other is in the rear position. The speed of the generated in a definiteratio to mov;ement of the rams and of the oscillating -when working by means of clutches not shown in the drawings.

What we claim. now as our invention is: 1. A machine for generatingthe teeth of bevel wheels, comprising a movable table, a blank carrier adjustably mounted on said table, means adapted to move said table together with the blank carrier around an axis passing through the vertex of the pitch cohe of the vblank, means adapted to rotate the blank aroun'd' its axis," the last mentioned means being operatively connected by means of a vertical shaft and flexible bands to said means adapted to move the table, means for varying the Speed of said movement of the blank-shaft relatively to the speed of the movement of the table and means to move the tool-carrying rams in such a way that the tools reciprocate along apex lines of the convex surface of the pitch cone; 7

2. A machine for generating the teeth of bevel-wheels, comprising a movable table, a blank-carrier adjustably mounted on said table, means adapted to oscillate said table together with the blank carrier around an axis passing through the vertex of the pitch cone of the blank fixed to said carrier, a member stationary relatively to one of said moving machine parts, means operatively connected to said member and carried partly by the table and partly by the blank carrier and adapted to impart a-rotary movement to the blank around its axis, said rotary movement being derived by means of a vertical shaft'and flexible bands from the 'oscillating motion imparted to the table,

means for varying the speed of said rotation of the blank about its axis relatively to the speed of the movement of the table, and means to move the-tool-carrying rams in such a way that thetools reciprocate along apex lines of the convex surface of the pitch cone.

3. A machine for generating the teeth of bevel wheels, comprising a stationary baseplate, a table movably mounted on the baseplate, ablank carrier adj ustably mounted on said table, means adapted to oscillate said table together with the blank carrier around an axis passing through the vertex of the pitch cone of the blank fixed to said carrier, a rolling segment provided with cylindrical facesand fixed to said base plate, means operatively connectedo to said rolling segment and carried partly by the table and partly by the blank carrier, two slides arranged, on the blank carrier and connected to said last mentioned means and to a spring device so as to receive a reciprocating motion,

a rolling segment provided with cylindrical} means connected to one of the slides and adapted to convert the reciprocating movement of the latter into a rotary movement of the blank around its axis and totransmit said motion tothe blank, means for varying the speed of said rotation of the blank about its axis relatively to the speed of the move-' ment of the table, and means to move the tool-carrying rams in such a way that the tools reciprocate along apex lines of the convex surface of the pitch cone.

4:. A machine for generating the teeth of bevel wheels, comprising a stationary baseplate, a table movably mounted on the baseplate, a blank carrier adjustably mounted on said table, means. adapted to oscillate said table together with the blankcarrier around an axis passing through the vertex of the pitch cone of the blank fixed to said carrier,

faces and fixed to said base plate, means operatively connected to said rolling segment and carried partly by the table and partly by the blank carrier, two horizontal slides arranged one above the other on the blank carrier, the lower of said slides being connected to said last mentioned means and to a spring device so as to receive a reciprocating motion, a rule acting as' a two-armed lever and transmitting the reciprocating motion of the lower slide to the upper slide, means connected to the upper slide adaptedto convert the reciprocating movement of the latter into 'a rotary movement ofthe blank around its axis and to transmit said motion to the blank, means tor'varying the speed of said rotation of the blank about its axis relatively to the speed; ot-the "movement of thetable, and means to m'ove'the 1 pitch cone of the blank fixed to said carrier, 116

a plurality of rolling segments and rolls with cylindrical faces adapted to work together by means of flexible steel bands and to transmit the oscillating motion of the table onto the horizontal slides and means to 120 convert it into a rotary motion and transmit it on to the axis about which the blank is mounted, means for varying the speed of said movement of the blankshaft relatively to the speed of the movement ofithe table 125 y and means to move the tool-carrying rams in such a way that the tools reciprocate along apex lines of the convex surface of the pitch cone.

6. A machine for generating the teeth of 130 bevel wheels,'comprising a stationary base plate, a table movably mounted on the base plate, a blank carrier adjustably mounted on said table in such a way, that the carrier may be swung around a horizontal axis passing through the vertex of the cone and adjusted at a position corresponding to the angle of the pitch cone of a given blank, means adapted to oscillate said table together with the blank carrier about an axis passing through the vertex of the pitch cone, a stationary rolling segment provided with cylindrical faces and fixed to said base plate, a vertical shaft mounted on said movable table, two rolls being fitted to said vertical shaft, the lower one being connected to one of the cylindrical faces of said stationary rolling segment by means of a steel band, a roll and a rolling segment adjustably fixed to one another and concentrically and rotatably mounted on the horizontal axis around which the blank carrier is adjusted, the last mentioned roll being connected by means of a steel band to the upper roll of the above mentioned vertical shaft, a roll'mounted on the blank carrier and connected by means of a steel band to the rolling segment on the blank carrier axis, two horizontal slides arranged one above the other on the blank carrier, the lower of said slides being connected with one end to the roll mounted. on the blank carrier and with the other end to a spring so as to receive a reciprocating motion, a compensating rule acting as a twoarmed lever and swinging around a pivot mounted on a sliding piece, which rule transmits the reciprocating motion of the lower slide to the upper slide, a hollow shaft rotatably mounted on the blank carrier and adapted to take up the blank shaft, steel bands connecting the upper slide to said blank shaft and converting the reciprocating motion of the slide into a rotary motion of the blank around its axis, means for varying the speed of said movement of the blank about its axis relatively to the speed of the movement of the table, and means to move the tool-carrying rams in such a way that the tools reciprocate alongapex lines of the convex surface of the pitch cone.

7. A machine for generating the teeth of bevel wheels,comprising va stationary base plate, a table movably mounted on' the base plate, a blank carrier adjustably mounted on said table in such a way, that'the carrier may be swun'g aroundahorizontal axis passing through the vertex of the cone and adjusted at a position correspondingto the angle of the pitch cone of a given blank, means adapted to oscillate said table together with the blank carrier about an axis passing through. the vertex of the-pitch cone, a stationary rolling segment provided with cylindrical faces of different radii for the purpose ofvarying the speed of the movement of the blank shaft relatively to the speed of the movement of the table and fixed to said base plate, a vertical shaft mounted on said movable table, two rolls being fitted to said vertical shaft, the lower one-being connected to one of the cylindrical faces of said stationary rolling segment by means of a'steel band, a roll and an exchangeable rolling segment for the purpose of varying the blank carrier, the lower of said slides, being connected with one end to the roll mounted on the blank carrier and with the other end to a spring so as to receive a reciprocating motion, a compensating rule acting as a two-armed lever and swinging around a pivot mounted on a sliding piece, a dovetailed guide fixed to the blank carrier along which said sliding piece of the compensating rule may be adjusted for the purpose of varying the speed of the movement of the blank shaft relatively to the speed of the movement of the table, which rule transmits the reciprocating motion of the lower slide to the upper slide, a hollow shaftrotatably mounted on the blank carrier and adapted to take up the blank shaft, steel bands connecting the upper slide to said blank shaft and converting the reciprocating motion of the slide into a rotary motion of the blank aroundits axis, means for varying the speed of said movement of the blank shaft relatively to the speed of the movement of the table, and means to move the tool-carrying rams in such a way, that the tools reciprocate along'apex lines of the convex surface of the pitch cone.

8. A machine for generating the teeth of bevel gears, comprising in combination, an oscillatory table, an angular-1y adjustable blank carrier mounted thereon, a shaft on said carrier adapted to carry a blank, the

axis of said shaft, the axis, of adjustment of said carrier and the axis of the table passing through a single point, means to OS- cillatesaid table, flexible connections between said table and blank carrying shaft to rotate said blank carrying shaft about its axis, and a tool'adapted to engage said blank along apex lines of the convex surface of the pitch cone of said blank. 4

9. A machine for generating the teeth of bevel gears, comprising in combination, an.

oscillatory table, an angularly adjustable apex lines of the convex surface of the pitch coneof said blank.

10. A machine for generating teeth of bevel gears comprising in combination, an oscillatory table, an angularly adjustable blank carrier mounted thereon, ashaft on said carrier adapted to carry a blank, the axis of said shaft, the axis of adjustment of said carrier and the axis of said ,table passing through a single point, means to oscillate said table, a vertical shaft and flexible connections between said table and blank carrying shaft to rotate said blank carrying shaft about its axis, means to vary the rotative movement of said blank about its axis, and a tool adapted to engage said blank along apex lines of the convex surface of the pitch cone of said blank.

11. A machine for generating teeth of bevel gears comprising in combination an oscillatory table, an angularly adjustable blank carrier mounted thereon, a shaft on said carrier adapted to carry a blank, the axis of said shaft, the axis of adjustment of said-carrier andthe axis of said table passing through a single point, means to oscillate said table, a vertical shaft mounted on said table to oscillate therewith, and flexible connections between said table and blank carrying shaft to rotate said blank carrying shaft aboutits axis and a tool adapted to engage said blank along apex lines of the convex surface of the pitch cone of said blank.

12. A .machine for generating teeth of bevel gears comprising in combination an oscillatory table, an angularly adjustable blank carrier mounted thereon, a shaft on said carrier adapted to carry a blank, the axis of said shaft, the axis of adjustment of said carrier and the axis of said table passing through a single point, means to oscillate said table, -a vertical shaft mounted on said table to oscillate therewith and flexible connections between said table and blank carrying shaft to rotate said blank carrying shaft about its axis, means to vary the rotative movement of said blank about its axis, and a tool adapted to engage said blank along apex lines of the convex surface of the pitch cone of said blank.

13. A machine for generating the teeth of bevel gears comprising in combination, an oscillatory table, an angularly adjustable blank carrier mounted thereon, .a

shaft on said carrier adapted to carry a.

blank, the axis of said shaft, the axis of adjustment of said carrier and the axis of said table passing through a single point, means to oscillate said table, means to rotate said blank carrying shaft about its axis, said means comprising rolling segments, a

shaft mounted on and oscillating with said table and flexible connections engaging said segments between said table and blank carrying shaft, and a tool adapted to. engage said blank along apex lines of the convex surface of the pitch cone of said blank.

In testimony that we claim the foregoing as our invention, we have si ned our names.

MAX AAG. RICHARD FREY. 

